Molecular dynamics simulation study of nonlinear optical response of fluids

Abstract

We present a molecular theory and molecular dynamics simulation of the transient nonlinear optical response measured in impulsive stimulated light scattering (ISS) and optical Kerr effect (OKE) experiments. The dipole-induced-dipole model is used to calculate the interaction-induced polarizability and ISS and OKE dynamic response functions of liquid CS 2 and compressed supercritical CO 2. We find that rotational relaxation dominates the long-time response and that “collision-induced” polarizability dynamics influences strongly the subpicosecond response of both fluids. These “collision-induced” effects are emphasized in the ISS signal, where they account for most of the peak intensity in the case of the highly polarizable CS 2.